1. Field of the Invention
The present invention relates to an image recording apparatus of an ink-jet type or the like, and more particularly to a structure of a supporting device of a carriage on which a recording head is mounted.
2. Description of the Related Art
A dominating conventional image recording apparatus is such that for example, as disclosed in JP-A-5-270091 (see FIGS. 1 to 4), in order to support a carriage carrying a recording head in such a manner that it can reciprocate in a main scanning direction, the carriage is slidably supported by a cylindrical guide shaft.
According to the cylindrical guide shaft, because of excellent size accuracy, high rigidity, a variation of a so-called paper gap between the nozzle surface of the recording head and the surface of a recording medium can be made small, and a high quality recording image can be easily obtained, however, the cost is high. Besides, when the carriage is detached from the guide shaft for maintenance, exchange or the like, the guide shaft is first detached from a frame, and further, the carriage must be detached from the guide shaft, while a procedure opposite thereto must be carried out at the time of assembly. Thus, there is a problem that the mounting of the carriage is very difficult.
For the purpose of reducing the cost, in JP-A-2002-254746 (see FIG. 2), a first carriage guide plate having a Z-shaped section is formed by cutting and raising at a halfway part, in the height direction, of a main frame provided to stand in the vertical direction, and a first guide part protruded downward from one lower surface of a carriage is brought into contact with an upper surface of a horizontal first position regulating plate. A third guide part laterally protruded from the lower part of the carriage so as to face the lower surface (sliding surface) of the first guide part is made to face the lower surface of the first position regulating plate.
Besides, at a part protruded downward from a side part of the carriage to have a U shape, a pair of second guide parts are provided to hold both the front and back surfaces of a second position regulating plate obtained by bending the tip of the first position regulating plate vertically upward.
Further, the lower surface (sliding surface) of a fourth guide part protruded downward from the other lower surface of the carriage is brought into contact (slide contact) with a third position regulating surface (upper surface) of the horizontal second carriage guide plate.